Is my new adjustable gas block bad?

[C-130 Dude]

On every AR whether it be in 10 or 15 no matter the cartridge port size does make a difference and matter! With AP barrels using standard rifle length gas in 6.5creed I use standard weight spring, buffer and non-adjustable gb. Others using standard length and +2 gas has been a challenge, but workable outcome. +2 isn't needed unless it's a short mag, then it's most likely needed due to way more gas volume at sustained pressure.

Gas tuning is a real pain. Can you say mil spec.....

 

[Tidus56]

Go figure...

Yeah I am still lost on why this happened.

 

[cohunt]

I guess I should ask if you run any type of adj gas block. I was saying excess gas as used in the bolt cycling process. As in getting rid of any you dont need to operate the bcg by venting it. Gas quantity for the bullet is controlled by the gas port size and length of gas tube (to a degree). Having to large a gas port can indeed rob the bullet push due to waist. Allowing maximum gas availability for bullet push is a givin. AR tuning is the biggest challange when setting up a self built AR. There are times when you dont need to use an adj gas block. I need to because I shoot a variety of bullet weights and vary from suppressed to non suppressed. I have found that the large frame AR calibers can be very picky on setup. Causing a multitude of gas cycling problems. It's much less of a headache to use good springs and buffer weights and use the adj gas block to tune it. As always you need to get the spring and buffer weight combo as correct as possible to begin with. My experience here is a product of 40+ years of doing AR setups. Of course others have a different approach. It's all good in the end. Stay date and have fun.

Yes- I use slr blocks on all my ar's

It's a complicated equation that uses the pressure (ammo related) and volume (gas hole size and gas tube length related) over a certain amount of time (dwell time)

Lots of things can change variables in the system-- ammo pressure/speed, powder burn rates, gas hole size ( this can be changed with an adj gas block) , gas tube length, barrel length, bcg weight, spring rate, buffer weight

For each set of variables a certain volume of gas at a certain pressure over a certain length of time is required to properly operate the bcg system--- anything "extra" isn't really extra- it should be kept in the barrel if possible. I used the bolt gun as a comparison because there is no "extra" gas in that system as anyone can see-- its all used for 1 purpose of getting the bullet out of the barrel. Why vent gas when it can be used to push that bullet a few fps faster?

I've done quite a bit of testing changing out components and with the sa "venting system"--- there was a very small loss in muzzle velocity that I found--- most handloaders strive to get the highest velocity with greatest accuracy possible-- why toss even a small amount of that hard work/speed out the door if it's not necessary?

There is no "extra" gas when properly adjusted.

I've run titanium carriers, lightweight springs, and ultralight 1oz buffers to decrease lock time and increase cyclic rate and every system can be balanced using an adjustable gas block--- the lighter the components, the less forgiving the adjustments but you can make them work with the right gas block.

I never understood the principles behind letting gas out of the system in the sa blocks--- I gave them a try and prefer slr blocks .

 

[C-130 Dude]

Yes- I use slr blocks on all my ar's

It's a complicated equation that uses the pressure (ammo related) and volume (gas hole size and gas tube length related) over a certain amount of time (dwell time)

Lots of things can change variables in the system-- ammo pressure/speed, powder burn rates, gas hole size ( this can be changed with an adj gas block) , gas tube length, barrel length, bcg weight, spring rate, buffer weight

For each set of variables a certain volume of gas at a certain pressure over a certain length of time is required to properly operate the bcg system--- anything "extra" isn't really extra- it should be kept in the barrel if possible. I used the bolt gun as a comparison because there is no "extra" gas in that system as anyone can see-- its all used for 1 purpose of getting the bullet out of the barrel. Why vent gas when it can be used to push that bullet a few fps faster?

I've done quite a bit of testing changing out components and with the sa "venting system"--- there was a very small loss in muzzle velocity that I found--- most handloaders strive to get the highest velocity with greatest accuracy possible-- why toss even a small amount of that hard work/speed out the door if it's not necessary?

There is no "extra" gas when properly adjusted.

I've run titanium carriers, lightweight springs, and ultralight 1oz buffers to decrease lock time and increase cyclic rate and every system can be balanced using an adjustable gas block--- the lighter the components, the less forgiving the adjustments but you can make them work with the right gas block.

I never understood the principles behind letting gas out of the system in the sa blocks--- I gave them a try and prefer slr blocks .

Well said. It would be nice if it wasn't so darn complicated. Oh well...By the way, what is your gas port size on your barrels? Just curious. I have my barrels set to .098. Doesn't really matter, the adj gas block regulates all throughput. I have a box of springs, buffers, and other components that I seem to dust off every time I get involved with another AR build. Only to go through the same test and replace process every time. One of these days I will start using the exact same parts every build to ease my pain. ...Naahhh. Where is the fun in that?

 

[HSmithTX]

I honestly don't remember the exact adjustments, from memory you start in restriction mode and adjust into venting mode? I know I followed the directions to the letter the first time and no issues, and I thought I could save some steps (ammo) by doing it my way the second time. I didn't. I opened it fully so it was venting max and then closed it several clicks at a time until I got function, tested with can on and off the rifle. I don't have the rifle or the instructions near me to review.

 

[lyle2231]

I opened the gas block 4.5 turns as the directions stated. It should have been fully open at that time. However, I couldn't get the bolt to lock back. I started to continue opening the valve until I got it open 9.5 turns. Only then did it lock back the bolt. Then opened it one more turn as I was instructed. Sound familiar???

My experience is with JP. Watched the video first then went to the range. So far so good.

 

[ARlife4me]

My unknown setting for new gas blocks and or new builds is to set it at 50% and go from there. Usually not far off with factory ammo with most cartridges. I keep 3 in the mag so too know if it's short stroking or over gassed. I used to do the 1 in mag, but that was the worst on figuring out the possible issue(s)!

 

[ObiWanKannoli]

Are you counting clicks or rotations? I think they say venting is like 4.5 rotations plus. I believe there are either 2 or 4 clicks per rotation.

 

[C-130 Dude]

Are you counting clicks or rotations? I think they say venting is like 4.5 rotations plus. I believe there are either 2 or 4 clicks per rotation.

Rotations.

 

[436]

Just did a rebarrell on my AR308. Decided to put a new Superlative adj gas block on it. Have used many different adj blocks on ar15 and ar10 in the past. Setting up this one is a bit different, to say the least. The gas pressure adjustments call for tuning excess gas out, not just blocking/limiting it. Followed directions by the letter. Even called the company tech line twice to make sure I was doing it right. So I pulled it off and put my old adj block on it. The old one works fine. The reason I wanted to try this one is to reduce the fouling problem standard adj gas blocks incur. The Superlative is supposed to vent excess gas out, not limit the gas via constricting it. Bottom line is this, has anyone had experience with this specific gas block? And did you have tuning issues? What did you do to get it running correctly? Is it possible I got a lemon???

Just guess... are you sure you have proper gas hole alignment? Good luck Cheers

 

[ARlife4me]

Also a clear gas tube and gas port. I would take apart the gb and recheck it without the tube attached.

 

[C-130 Dude]

Just guess... are you sure you have proper gas hole alignment? Good luck Cheers

I have built at least 25-30 AR guns in the past. Never had trouble till this one. I measured and confirmed the correct parts. Including the right length gas tube, rifle length dpms type. I have torn down and quadruple checked everything in the chain. I'm more than sure. I also confirmed the gas key seal, torque, and alignment. I removed the gas key and made sure it was flat. Then I use a tiny amount of Permatex brown carb sealer to ensure no leaks. Been doing this for years with no issues. Gas tube and gas block alignment is spot on. As always, I torqued the gas key screws and staked them. I'm stumped. I think I got a bad one.

 

[lyle2231]

I have built at least 25-30 AR guns in the past. Never had trouble till this one. I measured and confirmed the correct parts. Including the right length gas tube, rifle length dpms type. I have torn down and quadruple checked everything in the chain. I'm more than sure. I also confirmed the gas key seal, torque, and alignment. I removed the gas key and made sure it was flat. Then I use a tiny amount of Permatex brown carb sealer to ensure no leaks. Been doing this for years with no issues. Gas tube and gas block alignment is spot on. As always, I torqued the gas key screws and staked them. I'm stumped. I think I got a bad one.

 

[lyle2231]

Just trying to help you out…..what method did you use to align the gas block? I've used a "drop thru" plastic gauge I got from Unique Tech. Helped me get perfect gas hole alignment.